Recently I participated in my high school's musical The Addams Family. Many times during rehearsal I would go to the soundboard to get mic'd and then have my mic checked. I never really knew what a soundcheck composed of, so I asked my friend Jack who worked the soundboard. In the simplest terms possible, one listens to the speaker/singer and they determine which frequencies sound good in the room and which sound awful. The ones that sound awful are cut out. I thought it was pretty interesting, but had no idea how certain frequencies could simply be cut out or stopped from being amplified by the mic. Then today in my Physics C class, we learned that inductors can be used to do this. Inductors store a magnetic field like capacitors store an electric field. By using LC circuits, the soundboard is able to activate certain LC circuits that cut out different frequencies from exiting the microphone. I still don't know totally how LC circuits are able to work, but it was interesting realizes a real life use of them.